1. Field of the Invention
The present invention relates to an antenna, and more particularly to an antenna formed integrally into one piece.
2. Description of Related Art
With reference to FIG. 1, U.S. Pat. No. 6,741,219 discloses a parallel-feed planar high-frequency antenna (1) comprising a substrate and two dipole conducting strips. The substrate is made of dielectric material. The dipole conducting strips are mounted on opposite sides of the substrate. Each dipole conducting strip has a feed structure (10, 12), a feed point (24, 34), a plurality of feed lines (26, 28, 30, 32, 36, 38, 40, 42) and a plurality of half-wavelength dipoles (2a, 4a, 6a, 8a, 2b, 4b, 6b, 8b). The feed point (24, 34) is located on the feed structure (10, 12). The feed lines (26, 28, 30, 32, 36, 38, 40, 42) are connected to the feed point (24, 34). The half-wavelength dipoles (2a, 4a, 6a, 8a, 2b, 4b, 6b, 8b) are connected respectively to the feed lines (26, 28, 30, 32, 36, 38, 40, 42).
However, the structure of the antenna (1) is complicated. The dipole conducting strips are separated from each other instead of being formed into a single piece and are mounted respectively on the opposites sides of the substrate by adhesive so that fabricating the antenna (1) is time-wasting and lowers the production rate of the antenna (1). Furthermore, the substrate between the dipole conducting strips reduces gains of the antenna.
To overcome the shortcomings, the present invention provides an antenna to mitigate or obviate the aforementioned problems.